Heat treating method and heat treating apparatus

ABSTRACT

Disclosed is a heat treating method for heating a target substrate by means of light irradiation, in which a light irradiation treatment is applied to the target substrate a plurality of times such that adjacent light irradiated regions on the target substrate partially overlap with each other and that the adjacent light irradiated regions do not overlap with each other in the light irradiating periods.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Applications No. 11-267654, filed Sep.21, 1999; and No. 11-273213, filed Sep. 27, 1999, the entire contents ofwhich are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to a heat treating method and aheat treating apparatus.

[0003] In the manufacture of a semiconductor device or a liquid crystaldevice, the nonuniformity in the temperature of resist or a basesubstrate in heating or cooling a target substrate to be processed isreflected on the nonuniformity in the size of the pattern. Thus, withminiaturization of the pattern, the temperature control of a higherprecision is required.

[0004] For example, in a post exposure baking (PEB), which is one of themanufacturing steps of a photomask, the uniformity of the temperaturewithin a plane of a photo mask blank is very important. It was customaryin the past to employ a heating method using a heater in the PEB.

[0005] However, the following problem is generated in the heater heatingsystem. Specifically, in the normal state, a good temperature uniformityis exhibited within a plane of a photo mask blank. However, in thetransition period during which the photo mask blank is being heated, atemperature distribution is derived within a plane of the photo maskblank from the low heat conductivity and the large heat capacity of thequartz substrate, giving rise to a problem that the uniformity in thepattern size within the plane of the photo mask blank is made poor.

[0006] In view of the problem noted above, a lamp heating system isbeing studied. However, the following problem is generated in the caseof the conventional lamp heating system. Specifically, in the lampheating system, the uniformity of illuminance is poor within a lampirradiating region, giving rise to a temperature drop in the boundaryregion between adjacent lamp irradiating regions. As a result, atemperature distribution is generated in the photo resist.

[0007] Also, in the lamp heating system, it is possible to heatselectively a target thin film to be heated such as resist or a lightshielding film by selecting appropriately the wavelength of the lightemitted from the lamp. However, since the target thin film is heatedselectively, a large temperature difference is generated between thetarget thin film and the quartz substrate, making it difficult toperform the temperature control with a high accuracy.

BRIEF SUMMARY OF THE INVENTION

[0008] A first object of the present invention is to provide a heattreating method and a heat treating apparatus capable of making uniformthe light intensity distribution caused by the light irradiation andalso capable of making uniform the temperature distribution of a targetsubstrate to be heated.

[0009] A second object of the present invention is to provide a heattreating method and a heat treating apparatus capable of performing thetemperature control with a high accuracy.

[0010] According to a first aspect of the present invention, there isprovided a heat treating method for heating a target substrate by meansof light irradiation, wherein a light irradiation treatment is applied aplurality of times to the target substrate such that the adjacent lightirradiating regions of the target substrate are allowed to partiallyoverlap each other and that the light irradiating periods of theadjacent light irradiating regions do not overlap with each other.

[0011] In the first aspect of the present invention, it is desirable forthe light irradiation treatment that is applied a plurality of times tothe target substrate to be performed by changing the light irradiatingregions by a predetermined order such that the adjacent lightirradiating regions are allowed to partially overlap with each other.

[0012] In the first aspect of the present invention, it is desirable forthe light irradiation treatment that is applied a plurality of times tothe target substrate to be performed by a plurality of irradiating lightgenerating sections arranged to conform with the light irradiatingregions and arranged such that the adjacent light irradiating regionsare allowed to partially overlap with each other.

[0013] In general, the light intensity in the peripheral portion of thelight irradiating region is lower than that in the central portion.According to the first aspect of the present invention, it is possibleto increase the light intensity in the peripheral portion (overlappingregion) of the light irradiating regions so as to make the lightintensity distribution uniform over the entire region of the substrate.Also, since the irradiating periods are not overlapped, the succeedinglight irradiation can be performed after the temperature of the lightirradiated region is lowered sufficiently. Where the light irradiatingperiods are allowed to overlap with each other, it is necessary to carryout a complex control in view of the effect of the heat from theadjacent light-irradiating region. In the present invention, however, itis possible to suppress the effect of the heat from the adjacent lightirradiating region, leading to a simple temperature control so as tomake it possible to render easily the light intensity distributionuniform. It follows that, where the present invention is applied to thebaking of, for example, a photo resist film, the distribution of energyimparted to the photo resist film can be made uniform, making itpossible to pattern the photo resist film with a high accuracy.

[0014] According to a second aspect of the present invention, there isprovided a heat treating method for heating a target substrate byirradiation with light, wherein a light irradiation treatment is appliedto the target substrate such that the light irradiating regions of thetarget substrate do not overlap with each other, the light irradiationtreatment being performed by using an irradiating light adjusted suchthat the distribution of the light intensity within the lightirradiating region of the target substrate is rendered uniform.

[0015] In the second aspect of the present invention, it is desirablefor the light irradiation treatment applied to the target substrate tobe performed by changing the light irradiating regions by apredetermined order such that the light irradiating regions do notoverlap with each other.

[0016] In the second aspect of the present invention, it is desirablefor the light irradiation treatment applied to the target substrate tobe performed by using a plurality of irradiating light generatingsections arranged to conform with the light irradiating regions andarranged such that the light irradiating regions do not overlap witheach other.

[0017] According to the second aspect of the present invention, used isan irradiating light adjusted to permit the light intensity distributionto be uniform and the light irradiating regions do not overlap with eachother, making it possible to render the light intensity distributionuniform over the entire substrate. Also, the energy imparted to thesubstrate can be made uniform over the entire region of the substrate.

[0018] According to a third aspect of the present invention, there isprovided a heat treating apparatus for heating a target substrate bymeans of light irradiation, comprising a substrate support section forsupporting the target substrate, an irradiating light generating sectionfor irradiating the light irradiating regions of the target substratesupported by the substrate support section, and a light irradiatingregion changing section for changing the light irradiating regions ofthe target substrate irradiated with the light generated from theirradiating light generating section.

[0019] According to a fourth aspect of the present invention, there isprovided a heat treating apparatus for heating a target substrate bymeans of light irradiation, comprising a substrate support section forsupporting the target substrate, a plurality of irradiating lightgenerating sections arranged to conform with the light irradiatingregions of the target substrate supported by the substrate supportsection and arranged such that the light irradiating regions do notoverlap with each other, the irradiating light generating sectiongenerating an irradiating light adjusted to permit the light intensitydistribution to be uniform within the light irradiating region of thetarget substrate.

[0020] According to a fifth aspect of the present invention, there isprovided a heat treating method for heating a target substrateconsisting of a base substrate and a thin film formed on the basesubstrate by a heating section, comprising the steps of detectingtemperature information relating to temperature T₁ of the thin film andtemperature T₂ of the base substrate, and controlling the heatingsection on the basis of temperature T₁ of the thin film, temperature T₂of the base substrate, which are obtained from the temperatureinformation, and a target temperature T_(s) at which the thin film is toarrive.

[0021] Where a thin film formed on a base substrate is selectivelyheated, a large temperature difference tends to be generated between thethin film and the base substrate. According to the fifth aspect of thepresent invention, the heating section is controlled in view of thetemperature T₂ of the base substrate in addition to the targettemperature T_(s) and the temperature T₁ of the thin film, with theresult that the temperature control can be performed with a highaccuracy even if there is a large temperature difference between thethin film and the base substrate.

[0022] In the fifth aspect of the present invention, it is desirable fora plurality of heating periods to be different from each other in thecontrol characteristics of the heating section. Since the plural heatingperiods are made different from each other in the controlcharacteristics, it is possible to perform the temperature control moreaccurately with the hunting suppressed.

[0023] Also, it is desirable for the control characteristics to berepresented by a function including the temperature T₁ of the thin filmand the temperature T₂ of the base substrate in at least one heatingperiod.

[0024] Also, it is desirable for the control characteristics to be madedifferent at time t_(a) when, or before, the temperature T₁ of the thinfilm arrives at the target temperature T_(s).

[0025] Also, it is desirable to determine the time t_(a) by estimatingthe time when the temperature T₁ of the thin film will arrive at thetarget temperature T_(s) of the thin film on the basis of thetemperature T₁ of the thin film and the elevation rate of thetemperature T₁ and by utilizing the result of the estimation.

[0026] According to a sixth aspect of the present invention, there isprovided a heat treating apparatus for heating a target substrateconsisting of a base substrate and a thin film formed on the basesubstrate, comprising a heating section for heating the targetsubstrate, a temperature detecting section for detecting temperatureinformation relating to temperature T₁ of the thin film and temperatureT₂ of the base substrate, and a control section for controlling theheating section on the basis of the temperature T₁ of the thin film, thetemperature T₂ of the base substrate, which are obtained from thetemperature information detected by the temperature detecting section,and a target temperature T_(s) at which the thin film is to arrive.

[0027] In the sixth aspect of the present invention, it is desirable forthe temperature detecting section to have construction (1) or (2) givenbelow:

[0028] (1) It is desirable for the temperature detecting section to havea first detecting section and a second detecting section each arrangedon the side of that surface of the base substrate on which the thin filmis formed, the first detecting section serving to detect a light havinga wavelength A1 that permits the temperature information of the thinfilm to be selectively obtained, and the second detecting sectionserving to detect a light having a wavelength B1 that permits thetemperature information of at least the base substrate to be obtained.To be more specific, it is desirable for the first temperature detectingsection to detect a light having a wavelength that is not transmittedthrough the thin film and for the second temperature detecting sectionto detect a light having a wavelength that is transmitted to some extentthrough the thin film and that is also transmitted to some extentthrough the base substrate.

[0029] (2) It is desirable for the temperature detecting section to havea first detecting section arranged on the side of a first surface of thebase substrate on which the thin film is formed and a second detectingsection arranged on the side of a second surface of the base substratewhich is opposite to the first surface, the first detecting sectionserving to detect a light having a wavelength A2 that permits thetemperature information of the thin film to be selectively obtained, andthe second detecting section serving to detect a light having awavelength B2 that permits the temperature information of at least thebase substrate to be obtained. To be more specific, it is desirable forthe first detecting section to detect a light having a wavelength thatis not transmitted through the thin film, and for the second detectingsection to detect a light of a wavelength that is transmitted to someextent through the base substrate.

[0030] The target substrate used in the present invention consists of,for example, a quartz substrate used as the base substrate and aphotosensitive film such as a resist film and a light shielding filmsuch as a chromium film used as the thin film.

[0031] In each of constructions (1) and (2) given above, the firsttemperature detecting section is arranged on the side of that surface ofthe base substrate on which the thin film is formed. Therefore, it ispossible to obtain the temperature information of the thin film alone bysetting the wavelength A1 or A2 to fall within an appropriate range.Also, in construction (1), the second temperature detecting section isarranged on the side of that surface of the base substrate on which thethin film is formed. Thus, it is possible to obtain the temperatureinformation of the base substrate by setting the wavelength B1 to fallwithin an appropriate range, though the thin film is interposed betweenthe second temperature detecting section and the base substrate. Also,in construction (2), the second temperature detecting section isarranged on the side of the second surface of the base substrate whichis opposite to the first surface. Thus, the thin film is not interposedbetween the second temperature detecting section and the base substrate,making it possible to obtain the temperature information of the basesubstrate alone by setting the wavelength B2 to fall within anappropriate range.

[0032] Additional objects and advantages of the invention will be setforth in the description which follows, and in part will be obvious fromthe description, or may be learned by practice of the invention. Theobjects and advantages of the invention may be realized and obtained bymeans of the instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0033] The accompanying drawings, which are incorporated in andconstitute a part of the specification, illustrate presently preferredembodiments of the invention, and together with the general descriptiongiven above and the detailed description of the preferred embodimentsgiven below, serve to explain the principles of the invention.

[0034]FIG. 1 schematically shows the construction of a heat treatingapparatus according to a first embodiment of the present invention;

[0035]FIG. 2 is a graph showing the relationship between the wavelengthand the substrate transmittance according to the first embodiment of thepresent invention;

[0036]FIG. 3 shows the positional relationship between the heatingregion and the light irradiating region according to the firstembodiment of the present invention;

[0037]FIG. 4 shows the light intensity distribution within the lightirradiating region according to the first embodiment of the presentinvention;

[0038]FIGS. 5A and 5B are graphs showing the temperature histories ofthe quartz glass substrate, the light shielding film and the photoresistfilm according to the first embodiment of the present invention;

[0039]FIGS. 6A to 6D show the transmittance and reflectance of aninfrared ray according to the first embodiment of the present invention;

[0040]FIGS. 7A and 7B show the positional relationship between adjacentlight irradiating regions according to the first embodiment of thepresent invention;

[0041]FIG. 8 schematically shows the construction of a heat treatingapparatus provided with a plurality of infrared ray sensors according tothe first embodiment of the present invention;

[0042]FIG. 9 schematically shows the construction of a heat treatingapparatus according to a modification of the first embodiment of thepresent invention;

[0043]FIG. 10 schematically shows the construction of a heat treatingapparatus according to a second embodiment of the present invention;

[0044]FIG. 11A shows the layout of the light sources in a heat treatingapparatus according to the second embodiment of the present invention;

[0045]FIG. 11B is a plan view showing the slit in the heat treatingapparatus according to the second embodiment of the present invention;

[0046]FIG. 12 is a plan view showing a gist portion of the heat treatingapparatus according to the second embodiment of the present invention;

[0047]FIG. 13 is for explaining the heat treating method according tothe second embodiment of the present invention;

[0048]FIG. 14 shows the layout of the light sources in the heat treatingapparatus according to a first modification of the second embodiment ofthe present invention;

[0049]FIG. 15 shows the layout of the light sources in the heat treatingapparatus according to a second modification of the second embodiment ofthe present invention;

[0050]FIG. 16 is for explaining the heat treating method according to athird modification of the second embodiment of the present invention;

[0051]FIGS. 17A and 17B are for explaining the heat treating methodaccording to a third modification of the second embodiment of thepresent invention;

[0052]FIG. 18 schematically shows the construction of a heat treatingapparatus according to a fourth modification of the second embodiment ofthe present invention;

[0053]FIG. 19 schematically shows the construction of a heat treatingapparatus according to a third embodiment of the present invention;

[0054]FIG. 20A shows the gist portion of a heat treating apparatusaccording to a fourth embodiment of the present invention;

[0055]FIG. 20B is for explaining the heat treating method according tothe fourth embodiment of the present invention;

[0056]FIG. 21 schematically shows the construction of a heat treatingapparatus according to a fifth I5 embodiment of the present invention;

[0057]FIG. 22 is a graph showing the relationship between the intensityof the light transmitted through a chromium mask blank equipped with aresist and the wavelength of the light according to the fifth embodimentof the present invention;

[0058]FIG. 23 is a graph showing the changes with the heating time inthe temperatures of a target thin film to be heated and the quartzsubstrate as well as the temperature difference between the thin filmand the substrate according to the fifth embodiment of the presentinvention;

[0059]FIG. 24 is a graph showing the relationship between the voltageapplied to a halogen lamp and the heating time according to the fifthembodiment of the present invention;

[0060]FIG. 25 schematically shows the construction of a heat treatingapparatus according to a sixth embodiment of the present invention; and

[0061]FIG. 26 is a graph showing the changes with the heating time inthe temperatures of a target thin film to be heated and the quartzsubstrate as well as the temperature difference between the thin filmand the substrate according to the/sixth embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

[0062] Some embodiments of the present invention will now be describedwith reference to the accompanying drawings.

[0063] [First Embodiment]

[0064]FIG. 1 schematically shows the construction of a heat treatingapparatus according to a first embodiment of the present invention.

[0065] As shown in the drawing, a substrate 1 is arranged within theheat treating apparatus. A photo mask blank is used as the substrate 1.A post exposure baking is applied to the photo mask blank (substrate) 1within the heat treating apparatus. The photo mask blank 1 consists of atransparent quartz glass substrate 101 and a light shielding film 102. Aphotoresist film 103 is formed on the light shielding film 102. Thetransparent quartz glass substrate 101 is sized at, for example, 6inches and has a thickness of 0.25 inch. Also, the light shielding film102 is of a laminate structure consisting of a Cr film and aCrO_(x)N_(y) film.

[0066] An infrared ray sensor 2, which is arranged above the substrate 1supported by a substrate support section 5, serves to detect theradiation from the substrate 1. Based on the result of the detection,the surface temperature of the substrate 1 is calculated by a controldevice 6.

[0067] A light source 3 is arranged below the substrate 1 supported bythe substrate support section 5. Naturally, a heat treatment is appliedto the substrate 1 by the light source 3 from the back side of thesubstrate 1. A halogen lamp having, for example, the maximum output of300 W and the wavelength at the maximum output of 900 nm is used as thelight source 3. A plurality of light sources 3, which are mounted to alight source support section 30, are equidistantly arranged in theX-direction and the Y-direction. In this embodiment, 9 light sources arearranged in total such that 3 light sources are arranged in each of theX- and Y-directions. A cooling water supply pipe 30P for circulating acooling water is arranged within the light source support section 30.The light sources 3 and the surrounding regions are cooled by thecooling water circulated within the cooling water circulating pipe 30P.

[0068] A filter 4 and a light guide 20 are arranged between the lightsource 3 and the substrate support section 5. The filter 4 serves to cutthe light having a wavelength of about 1.4 μm and the light having awavelength not shorter than 2.2 μm, which are the wavelength of thelight absorbed by the transparent quartz glass substrate 101.

[0069] The light guide 20, which is arranged for the every light source3, is formed of, for example, a quartz glass rod (pillar) having arectangular or square cross section. The light guide 20 is formed tooutput efficiently the light emitted from the light source 3 to thesubstrate 1. Incidentally, the light guide 20 may consist of a glass rodhaving a hexagonal cross section or a circular cross section in additionto the rectangular cross section noted above.

[0070] The substrate support section 5 is mounted on a stage 50 movablein an X-direction, a Y-direction and a Z-direction. The stage 50 can bemoved in a predetermined direction by a driving section 51, and thedriving section 51 is controlled by a control device 6.

[0071] The control device 6 is connected to the infrared ray sensor 2and the light source 3. The voltage required for the light emission fromthe light source 3 is calculated in the control device 6 on the basis ofthe temperature information of the substrate 1 obtained by the infraredray sensor 2, and the calculated voltage is outputted to the lightsource 3.

[0072] A transfer arm 7 and a flow regulating plate 8 are connected tothe driving section 51. The transfer arm 7 serves to transfer thesubstrate 1 from outside the heat treating apparatus onto the substratesupport section 5, and also serves to transfer the substrate 1 to whicha heat treatment has been applied to the outside of the heat treatingapparatus. On the other hand, the flow regulating plate 8, which servesto prevent disturbance of the gas stream above the substrate 1, can bemoved by the driving section 51 in an X-direction, a Y-direction and aZ-direction.

[0073] These substrate support section 5, light source 3, infrared raysensor 2, etc. are isolated from the outside by an apparatus outer frame9 so as to form a measuring system in which the gas stream is notdisturbed. A dust filter 10 and a chemical filter 11 are mounted to theapparatus outer frame 9 so as to control the dust and the atmospherewithin the heat treating apparatus.

[0074] Incidentally, an exhaust duct (not shown) is connected to theheat treating apparatus. The gas generated during the heat treatingoperation is discharged to the outside through the exhaust duct, and thevapor of an organic material or the like is prevented by the exhaustduct from being attached to the inner wall of the heat treatingapparatus.

[0075] The heat treating method using the heat treating apparatus shownin FIG. 1 will now be described.

[0076] In the first step, prepared is a photo mask blank consisting ofthe transparent quartz glass substrate 101 and the light shielding film102 formed on the glass substrate 101, followed by coating the lightshielding film 102 with the photoresist film 103. It is possible to use,for example, a positive chemically amplified resist film having athickness of 500 nm as the photoresist film 103. Then, a light exposuretreatment is applied to the photoresist film 103 by using an electronbeam writing apparatus. The light exposure treatment is carried outunder the conditions of, for example, 50 keV and 8 μC/cm².

[0077] In the next step, the position of the substrate 1 is determinedby using a position aligning unit (now shown), followed by transferringthe substrate 1 from outside the heat treating apparatus into the heattreating apparatus by operating the transfer arm 7. Also, the flowregulating plate 8 is arranged in an appropriate position above thesubstrate 1, e.g., in a position about 5 mm above the substrate 1.Further, the filter 4 is arranged in an appropriate position below thesubstrate 1. The temperature measurement by the infrared ray sensor 2(which is a radiation thermometer) is started as soon as the substrate 1is mounted to the substrate support section 5. A trigger signal foroperating the infrared ray sensor 2 is delivered from the control device6.

[0078] The wavelength measured by the infrared ray sensor 2 is set at,for example, 11 μm. FIG. 2 is a graph showing the relationship betweenthe measured wavelength and the transmittance of the substrate 1. Asshown in FIG. 2, the transmittance of the substrate 1 is substantiallyzero in the wavelength range of about 2.7 μm to 2.8 μm and in the regionof 4.3 μm or more. By selecting the wavelength at which thetransmittance is substantially zero, the infrared ray sensor 2 isallowed to receive only the reflection from the photoresist film 103 andthe light shielding film 102 that are to be measured. In addition, theinfrared ray sensor 2 is allowed not to receive the radiation from thetransparent quartz glass substrate 101 and from the light source 3,which are not the objects to be measured. Also, by measuring thewavelength of 11 μm on the long wavelength side, it is possible to avoidthe influences of the spectral wavelength of water and carbon dioxidecontained in the air atmosphere.

[0079] In the next step, the substrate 1 is disposed on the substratesupport section 5, and the heating by the light source 3 is carried outa certainly period of time later. A low voltage of, for example, 1V isapplied to the light source 3 in the initial state in order to preventthe light source 3 from being turned on or off completely so as toprolong the life of the light source 3.

[0080] Then, the light irradiation is carried out several times suchthat the adjacent light irradiating regions 301, 302, 303, 304, etc. areallowed to overlap with each other, and that the light irradiatingperiods do not overlap with each other so as to apply a heat treatmentto the photoresist film 103 formed on the substrate 1, as shown in FIG.3. The adjacent light irradiated regions overlap with each other, withthe positions of the substrate 1 and the light source 3 held stationary.

[0081]FIG. 4 is a graph showing the light intensity distribution of thelight irradiation within the irradiated region on the substrate. Asapparent from the graph of FIG. 4, the light intensity is high in thecentral region and low in the peripheral region in the light irradiatedregion, e.g., the light irradiated region 301. To be more specific, thelight intensity in the outermost periphery of the light irradiatedregion 301 is lower by about 10% than the light intensity in the centralportion of the light irradiated region 301. In this embodiment, each ofthe light irradiated regions 301, 302, 303, 304, etc. is square and hasa size of 70 mm. Therefore, the light irradiation is carried out suchthat the light irradiated regions 301 and 302 are allowed to overlapwith each other by about 5 mm so as to prevent the light intensity frombeing lowered in the overlapping region between the light irradiatedregions 301 and 302. Incidentally, the decrease of the light intensityis not larger than 1% in the point about 5 mm inside the light guide 20shown in FIG. 1.

[0082] The heat treating method will now be described. In the firststep, the first light irradiation is performed so as to selectively heatthe light irradiated region 301 alone of the photoresist film 103. Whenthe temperature of the photoresist film 103 in the light irradiatedregion 301 is elevated to reach the temperature set in advance by thecontrol device 6, the input voltage is controlled at an interval of 0.5second so as to stabilize the temperature of the photoresist film 103.

[0083]FIG. 5A shows the temperature history of the quartz glasssubstrate 101, with FIG. 5B showing the temperature histories of thelight shielding film 102 and the photoresist film 103.

[0084] As shown in FIG. 5B, the temperature of the light shielding plate102 is elevated to reach 100° C. in about 10 seconds after start-up ofthe light irradiation. Then, the light irradiation is controlled by thecontrol device 6 such that the temperature of the light shielding film102 is made constant at 100° C. After the heat treatment by the lightirradiation is performed for 60 seconds, the voltage applied to thelight source 3 is lowered to a low voltage so as to stop the heattreatment by the light irradiation. As shown in FIG. 5A, the temperatureof the transparent quartz glass substrate 101 in this step is about 31°C., supporting that the temperature elevation of the transparent quartzglass substrate 101 can be suppressed in the case of using the filter 4,compared with the temperature of about 62° C. in the case where thefilter 4 is not used. The substrate 1 is cooled by stopping the heattreatment.

[0085] As shown in FIGS. 6A to 6D, a heat treatment can be appliedeffectively to the light shielding film 102 and the photoresist film 103while suppressing the temperature elevation of the transparent quartzglass substrate 101 by setting the wavelength of the light source 3 at1.3 μm or less or to fall within a range of between 1.5 μm and 2.1 μm.

[0086]FIG. 6A is a graph showing the relationship between the wavelengthof the light source 3 and the infrared ray transmittance in respect ofthe transparent quartz glass substrate 101. FIG. 6B is a graph showingthe relationship between the wavelength of the light source 3 and theinfrared ray transmittance in respect of the transparent quartssubstrate 101 having the light shielding film 102 formed thereon. FIG.6C is a graph showing the relationship between the wavelength of thelight source 3 and the infrared ray transmittance in respect of thetransparent quartz glass substrate 101 having the light shielding film102 and the photoresist film 103 formed thereon. Further, FIG. 6D is agraph showing the relationship between the wavelength of the lightsource 3 and the infrared ray reflectance in respect of the transparentquarts glass substrate 101 having the light shielding film 102 and thephotoresist film 103 formed thereon.

[0087] As shown in FIG. 6A, in the transparent quartz glass substrate101 used in this embodiment, the wavelength region absorbing the lightis present in the wavelengths of about 1.4 μm and not shorter than 2.2μm. In the other wavelength region, the transmittance is about 90% andthe remaining 10% of the light is almost reflected, with the result thatthe infrared ray is scarcely absorbed. It follows that the transparentquartz glass substrate is very unlikely to be heated.

[0088] The infrared ray transmitting through the transparent quartzglass substrate is incident on the light shielding film formed on thetransparent quartz glass substrate 101. As shown in FIG. 6B, the lighttransmittance tends to gradually increase with increase in thewavelength. However, because of the presence of the light shielding film102, the light transmittance is about 1% in a wavelength of 1 μm. Sincethe transmittance is increased with increase in the wavelength, it isdesirable to use the light having the wavelength of about 1 μm orshorter.

[0089] As shown in FIG. 6D, the reflectance of the transparent quartzglass substrate 101 having the light shielding film 102 formed thereonis about 50% in the wavelength of 1 μm. Therefore, the remaining 50% issupposed to have been absorbed by the light shielding film 102.

[0090] As shown in FIGS. 6B and 6C, the transparent quartz glasssubstrate having the photoresist film 103 formed thereon exhibits thetransmittance of the light having a wavelength of about 1.1 μm, which isabout 0.5% higher than that of the transparent quartz glass substrate101 not having the photoresist film 103 formed thereon. Since thereflectance of the light having a wavelength of about 1.1 μm is about30% as shown in FIG. 6D, it is highly possible for the photoresist film103 to absorb the light having the wavelength of about 1.1 μm.

[0091] As described above, where the filter 4 is arranged between thesubstrate 1 and the light source 3, it is possible to heat selectivelythe light shielding film 102 and the photoresist film 103 uponirradiation with the infrared ray without heating the transparent quartzglass substrate 101.

[0092] After the heat treatment (first light irradiation) applied to thelight irradiated region 301, the second light irradiation is applied tothe light irradiated region 302 by the light source 3 differing from thelight source 3 used for the first light irradiation, with the positionalrelationship between the substrate 1 and the light source 3 leftunchanged. After the light source 3 used for the first light irradiationis turned off, the light source 3 used for the second light irradiationis turned on. The second light irradiation is started when the substrate1 is cooled to, for example, room temperature. What should be noted isthat the first light irradiation and the second light irradiation do notoverlap with each other in the irradiating time such that theirradiating time for the second light irradiation deviates from theirradiating time for the first light irradiation.

[0093]FIGS. 7A and 7B show the relationship between the first lightirradiation and the second light irradiation. As shown in FIGS. 7A and7B, the light rays emitted from the adjacent light guides 20 are allowedto overlap with each other. In this embodiment, the size of each lightguide 20 is 65 mm square, and the size of the region irradiated with thelight emitted from the light guide 20 is 70 mm square, as shown in FIG.7A. It follows that the overlapping width of the adjacent lightirradiated regions is 5 mm. The overlapping region, which is provided soas to make the irradiated energy uniform over the entire region of thephotoresist film 103, is determined in view of the heating time of thesubstrate 1 and the thermal diffusion of the light shielding film 102.

[0094] The infrared ray sensor 2 is moved to a position conforming withthe light irradiated region 302 before the second light irradiation isperformed.

[0095] In the fashion described above, the third light irradiation tothe ninth light irradiation are carried out successively by the lightsource 3 so as to apply the heat treatment to the light irradiatedregions 303, 304, etc. as shown in FIG. 3, with the positionalrelationship between the substrate 1 and the light source 3 leftunchanged, thereby applying the heat treatment to the entire region ofthe photoresist film 103.

[0096] In the next step, a dip development is applied to the substrate 1after the post exposure baking so as to form an etching mask consistingof the photoresist film 103. It is possible to use, for example, “AD-10”(trade name of a developing solution manufactured by Kabushiki KaishaTama Kagaku) for the dip development. After the dip development, a dryetching is carried out by using the etching mask formed by the dipdevelopment so as to pattern the light shielding film 102. Then, theetching mask is removed, followed by performing a washing treatment anda drying treatment, thereby finishing preparation of a reticle.

[0097] The reticle thus prepared was found to have a dimensional erroron the plane of about 10 nm (3 σ), supporting that it was possible toprepare a reticle (chromium mask) of a high accuracy.

[0098] As described above, in this embodiment, the light irradiation isapplied a plurality of times to the portions of a low light intensity inthe overlapping regions between adjacent light irradiated regions 301,302, etc. so as to make uniform the energy imparted to the entire regionof the photoresist film 103 (the entire heating region). Therefore, thetemperature distribution can be made uniform over the entire photoresistfilm 103, making it possible to pattern the photoresist film 103 with ahigh accuracy. It should also be noted that, since the light shieldingfilm 102 is patterned by utilizing the etching mask made of thephotoresist film 103, it is possible to prepare a reticle having a highprecision pattern of the light shielding film 102.

[0099] It should also be noted that, if the light irradiation is appliedsimultaneously to the light irradiated regions 301, 302, etc., the heatis migrated among the light irradiated regions 301, 302, etc., making itnecessary to perform the control in view of the heat migration. In thisembodiment, however, the light irradiating periods do not overlap witheach other so as to decrease the migration of the heat among the lightirradiated regions. It follows that the temperature distribution in eachlight irradiated region can be controlled easily, making it possible torender uniform easily the temperature distribution over the entireregion of the photoresist film 103. For example, where the second lightirradiation is carried out before the temperature of the lightirradiated region 301 having the first light irradiation applied theretois lowered sufficiently, an excessive heat treatment is applied to thelight irradiated region 302 because of the influence of the heat fromthe light irradiated region 301.

[0100] Also, in this embodiment, the wavelength region of theirradiating light is selected appropriately, making it possible to heatselectively the light shielding film 102 and the photoresist film 103without heating the transparent quartz glass substrate 101. It followsthat the temperature distribution of the photoresist film 103 can bemade uniform.

[0101] Incidentally, the single infrared ray sensor 2 is moved in theembodiment described above. However, it is possible to arrange 9infrared ray sensors 2 to conform with the 9 light sources 3, i.e., 3×3,as shown in FIG. 8.

[0102] Also, in the embodiment described above, the light sources 3 areturned on one by one. However, it is possible to have a plurality oflight sources 3 turned on simultaneously when it comes to the regionswhere the light irradiated regions do not overlap with each other.

[0103] Further, in the embodiment described above, used was a substrate(mask blank) 1 having the light shielding film 102 formed on thetransparent quartz glass substrate 1. However, it is also possible touse a substrate (half tone mask) having a translucent film formed on thetransparent quartz glass substrate 101. It is possible to use as thetranslucent film a laminate structure consisting of a MoSi₂ film and aCr film laminated on the MoSi₂ film.

[0104] (Modification)

[0105]FIG. 9 schematically shows the construction of a heat treatingapparatus according to a modification of the first embodiment of thepresent invention. The constituents of the heat treating apparatuscorresponding to the constituents of the apparatus shown in FIG. 1 aredenoted by the same reference numerals so as to omit the detaileddescription thereof.

[0106] Nine light sources 3 (halogen lamps) are arranged in the heattreating apparatus shown in FIG. 1. In the modification shown in FIG. 9however, used is only one light source 3 (halogen lamp). Also, a lightsource support section 30 can be moved by the driving section 51 in thismodification. Further, the filter 4 and the light guide 20 can be movedin the X- and Y-directions.

[0107] For operating the heat treating apparatus shown in FIG. 9, thesubstrate 1 similar to that used in the apparatus shown in FIG. 1 isdisposed on the substrate support section 5, followed by applying a heattreatment to the substrate 1 by turning on the light source 3 asfollows.

[0108] In the first step, a heat treatment is applied to the first lightirradiated region 301 by the light source 3, as shown in FIG. 3. Thecontrol method of the heat treatment is equal to that describedpreviously in conjunction with the first embodiment.

[0109] To be more specific, after the heat treatment of the lightirradiated region 301 is finished by turning off the light source 3, thelight source support section 30 is moved so as to set the position ofthe second light irradiation at a position deviated by 60 mm in theX-direction. The width of the overlapping region between the first lightirradiated region 301 and the second light irradiated region 302 isabout 5 mm. The second light irradiation is started after the substrate1 is cooled to, for example, room temperature. What should be noted isthat the first light irradiation and the second light irradiation arecarried out not to overlap with each other in the irradiating time.

[0110] Then, the third light irradiation to the ninth light irradiationare carried out successively in the same fashion so as to finish theheat treatment applied to the entire region of the photoresist 103.Then, a developing treatment is applied to the photoresist film 103 asin the embodiment shown in FIG. 1, followed by patterning the lightshielding film 102 so as to obtain a reticle.

[0111] In the modification described above, the light irradiation iscarried out a plurality of times by moving the light source 3 (lightsource support section 30). Alternatively, it is possible to carry outthe light irradiation a plurality of times by moving the substrate 1(stage 50).

[0112] [Second Embodiment]

[0113]FIG. 10 schematically shows the construction of a heat treatingapparatus according to a second embodiment of the present invention. Asin the first embodiment, a photo mask blank equipped with a photoresistis used as the substrate 1 in the second embodiment, too.

[0114] The light source 3 is arranged below the substrate 1 supported bythe substrate support section 5, and a heat treatment is applied to thesubstrate 1 by the light source 3 from the back surface side of thesubstrate 1. A halogen lamp having, for example, the maximum output of300 W and the wavelength at the maximum output of 900 nm is used as thelight source 3.

[0115]FIG. 11A shows the layout of the light source 3, and FIG. 11B is aplan view of a slit 13. FIG. 12 is a plan view showing the positionalrelationship among the substrate 1, the substrate support section 5, thelight source 3 and the slit 13. The light source 3 consists of halogenlamps supported on a light source support section 30. As shown in thedrawings, a total of 34 halogen lamps are equidistantly arranged (i.e.,2 halogen lamps in the X-direction and 17 halogen lamps in theY-direction) on the light source support section 30. Each light source3, i.e., a single halogen lamp, is capable of irradiating a regionhaving a diameter of 15 mm. Therefore, the entire light source 3consisting of 34 halogen lamps is capable irradiating a region of 30mm×255 mm.

[0116] As shown in FIG. 10, the slit 13 is arranged between thesubstrate 1 and the light source 3 and is movable together with thelight source 3. In order to limit the light irradiating region of theentire light source 3, the slit 13 is provided with an opening 13H whichis 30 mm in the X-direction and 255 mm in the Y-direction. The width ofthe opening is narrowed in the central portion of the opening 13H so asto lower the irradiating light intensity (or to decrease the energyamount). In other words, the irradiating intensity of the light passingthrough the opening 13H is made uniform by narrowing the width of theopening 13H in the central portion where the irradiating intensity ishigh. In other words, the irradiating light is shaped to permit thelight intensity distribution to be made uniform within the lightirradiated region.

[0117] It should also be noted that the irradiating light intensity ismade nonuniform by the nonuniformity in the resistance value of thehalogen lamps constituting the light source 3. In order to overcome thisdifficulty, the irradiating light intensity for each halogen lamp (lightsource 3) is measured in advance, and a suitable voltage is suppliedfrom the control device 6 to each of the halogen lamps (light source 3)based on the result of the measurement so as to make uniform theirradiating light intensity.

[0118] The filter 4 consisting of two band-pass filters superposed oneupon the other is interposed between the light source 3 and the slit 13,as in the first embodiment of the present invention.

[0119] The substrate support section 5 is mounted on the stage 50movable in the X-direction, Y-direction and Z-direction. The stage 50can be moved in a predetermined direction by the driving section 51,which is controlled by the control device 6. The stage 50 and thedriving section 51 constitute a light irradiating position movingmechanism for changing the light irradiating position relative to theheating region of the substrate 1. Also, the light source supportsection 30 is connected to the driving section 51, making it possiblefor the light source support section 30 and the driving section 51 tocollectively constitute the light irradiating position moving mechanism.It basically suffices for the heat treating apparatus to comprise one ofthese two mechanisms, particularly, the latter light irradiatingposition moving mechanism.

[0120] The substrate support section 5 is provided with a frame 14surrounding the periphery of the substrate 1. The frame 14 is of alaminate structure consisting of a transparent quartz glass plate and alight shielding film material formed on the glass plate, like thesubstrate 1. Naturally, the substrate 1 and the frame 14 are equal toeach other in the heat conductivity, making it possible to render theheat diffusion from the substrate 1 uniform. Also, the surface of thesubstrate 1 coincides in height with the surface of the frame 14 underthe state that the substrate 1 is mounted on the substrate supportsection 14.

[0121] A reflecting plate 15 is arranged above the substrate 1. Thereflecting plate 15 serves to reflect the light transmitting through thesubstrate 1 so as to improve the heating efficiency of the substrate 1.The reflecting plate 15 can be moved in the X-direction, Y-direction andZ-direction by the driving section 51. It is possible for the reflectingplate 15 to be provided with a heater for controlling the temperatureequal to the heat treating temperature of the substrate 1. Theparticular reflecting plate 15 can be obtained by polishing the surfaceof an aluminum plate excellent in heat conductivity and by arranging aheater pattern on the back surface of the aluminum plate.

[0122] It is possible to use a black body plate capable of holding theenergy imparted by the light irradiation in place of the reflectingplate 15. As a base plate of the reflecting plate 15 and the black bodyplate, it is possible to use a metal plate such as a stainless steelplate in addition to the aluminum plate. The reflecting plate can beprepared by polishing the surface of a metal plate, and the black bodyplate can be prepared by spraying uniformly a black paint on the surfaceof a metal plate. Further, it is possible to use a light scatteringplate in place of the reflecting plate 15.

[0123] The apparatus outer frame 9, the dust filter 10, the chemicalfilter 11 and the exhaust duct (not shown) included in the heat treatingapparatus according to the second embodiment of the present inventionare equal to those included in the heat treating apparatus of the firstembodiment described previously.

[0124] The heat treating method using the heat treating apparatus shownin FIG. 10 will now be described.

[0125] In the first step, the substrate 1 equal to that shown in FIG. 1is disposed on the substrate support section 5 and heated by the lightsource 3 as described below.

[0126] Specifically, a heat treatment is applied to a light irradiatedregion 401 by the light source 3 as shown in FIG. 13.

[0127] After the heat treatment applied to the light irradiated region401, the light source support section 30 is moved by 30 mm in theX-direction so as to set a second light irradiating position 402. Inthis step, the edge of the second light irradiated region 402 is alignedwith the edge of the first light irradiated region 401. In other words,the second embodiment differs from the first embodiment in that the twoadjacent light irradiated regions 401 and 402 do not overlap with eachother. The second light irradiation is started after the temperature ofthe substrate 1 is lowered, for example, to room temperature. In otherwords, the first light irradiation and the second light irradiation donot overlap with each other in the light irradiation time.

[0128] Likewise, the third light irradiation et seq. are consecutivelycarried out such that the adjacent light irradiated regions do notoverlap with each other so as to finish the heat treatment over theentire region of the photoresist film 103. Then, a developing treatmentis applied to the photoresist film 103 as in the first embodiment shownin FIG. 1, followed by patterning the light shielding film 102 so as tofinish preparation of a reticle.

[0129] The reticle thus prepared was found to have a dimensional errorof 8 nm (3 σ) within the plane, supporting that it is possible toprepare a high precision reticle (chromium mask).

[0130] As described above, in the second embodiment, the heat treatmentis applied to the photoresist film 103 by using the slit 13 so as tomake the light intensity distribution uniform within the lightirradiated region. As a result, the light intensity distribution is madeuniform over the entire region of the photoresist film 103. It followsthat the second embodiment makes it possible to prepare a reticle havinga high precision pattern of the light shielding film 102, like the firstembodiment described previously.

[0131] Also, the heat treating apparatus of the second embodimentcomprises a reflecting plate, a black body plate or a light scatteringplate. In this case, the light emitted from the light source 3 isreflected by the reflecting plate toward the substrate 1. Alternatively,the light energy emitted from the light source 3 is held by the blackbody plate, or the light from the light source 3 is scattered by thelight scattering plate toward the substrate 1. It follows that theheating efficiency by the light irradiation is improved.

[0132] Also, the reflecting plate 15 is provided with a heater, makingit possible to improve further the heating efficiency by the lightirradiation. To be more specific, it was possible to improve the heatingefficiency by about 2%, and it was also possible to improve theuniformity of the temperature of the photoresist film 103 formed on thesubstrate 1. Particularly, the concentric size distribution derived fromthe temperature distribution within the reticle plane was markedlyimproved so as to obtain a reticle of a high accuracy.

[0133] Further, the substrate 1 is surrounded by the frame 14 having astructure similar to that of the substrate 1, making it possible toprevent the temperature in the peripheral region of the substrate 1 frombeing lowered. Thus, the uniformity of the heating temperature of thesubstrate 1 can be improved.

[0134] In the second embodiment described above, the light source 3 ismoved with the substrate 1, i.e., the stage 50, fixed. However, it isalso possible to move the stage 50 with the light source 3 fixed.

[0135] Also, in the second embodiment described above, the light sourcefor a certain light irradiated region is turned on, followed by turningoff the light source so as to move the light source to the next lightirradiating region. However, it is also possible to scan the lightsource continuously with the light source kept turned on continuously.

[0136] (Modification 1)

[0137]FIG. 14 shows the layout of the light source 3 according to afirst modification of the second embodiment of the present invention. Asshown in the drawing, the light sources 3 (halogen lamps) are positionedto form two columns arranged side by side in the X-direction in theupper and lower regions of the array of the light sources 3, with thelight sources 3 being positioned to form a single column in the centralregion of the array of the light sources 3. In this modification, a slitis not required, and the irradiating light intensity in the lightirradiated regions is made uniform by the arrangement of the lightsources 3. Since the slit 13 is not required, the construction of theheat treating apparatus can be simplified.

[0138] (Modification 2)

[0139]FIG. 15 shows the layout of the light source 3 according to asecond modification of the second embodiment of the present invention.As shown in the drawing, the light sources 3 include light sources 3Larranged in the upper and lower regions of the array of the lightsources 3 and light sources 3S arranged in the central region of thearray of the light sources 3. In this modification, the lightirradiating intensity for the light source 3L is higher than that forthe light source 3S. It follows that the light irradiating intensity ofthe light irradiated region can be made uniform by the arrangement ofthe light sources 3L and 3S. Needless to say, a slit is not required inthis modification. Since the slit 13 is not required, the constructionof the heat treating apparatus can be simplified.

[0140] (Modification 3)

[0141] In each of the modifications described above, the entire lightsource is vertically oblong, and the light irradiated regions are movedin the X-direction. In the third modification, however, the lightirradiated regions are moved in the X-direction and the Y-direction. Thebasic construction of the apparatus is equal to that shown in FIG. 9,and a single light source 3 is moved in the X-direction and theY-direction. In the third modification, however, the irradiating lightis shaped by, for example, a slit to permit the light intensitydistribution uniform within the light irradiated region, as in theembodiment described previously.

[0142] In this modification, the substrate 1 equal to that shown in FIG.1 is disposed on the substrate support section 5, followed by performingthe heat treatment by the light source 3 as follows.

[0143] In the first step, a heat treatment is applied to a lightirradiated region 411 by the light source 3, as shown in FIG. 16.

[0144] After the heat treatment applied to the light irradiated region411, the light source support section 30 is moved in the X-direction soas to set a second light irradiating position. In this step, the edge ofthe second light irradiated region 412 is aligned with the edge of thefirst light irradiated region 411. In other words, the adjacent lightirradiated regions 411 and 412 do not overlap with each other. Thesecond light irradiation is started after the substrate 1 is cooled to,for example, room temperature. In other words, the first lightirradiation and the second light irradiation do not overlap with eachother in the light irradiating time.

[0145] Likewise, the third light irradiation et seq. are consecutivelycarried out to cover the light irradiated regions 413, 414, 415, etc.such that the adjacent light irradiated regions do not overlap with eachother so as to finish the heat treatment over the entire region of thephotoresist film 103. Then, a developing treatment is applied to thephotoresist film 103 as in the first embodiment shown in FIG. 1,followed by patterning the light shielding film 102 so as to finishpreparation of a reticle.

[0146] The moving method of the light source is not limited to theexample described above. For example, it is possible to move the lightsource in the order shown in FIG. 17A or 17B.

[0147] (Modification 4)

[0148]FIG. 18 schematically shows the construction of a heat treatmentaccording to a fourth modification of the second embodiment of thepresent invention. The irradiating light is shaped in this modification,too, to permit the light intensity distribution to be uniform within thelight irradiated region.

[0149] In each of the modifications described above, the lightirradiation is carried out by moving the substrate or the light source.In the fourth modification, however, the light irradiation is carriedout with the positions of the substrate and the light source heldstationary. Therefore, required are 9 infrared ray sensors 2corresponding to the 9 light sources (3×3).

[0150] Also, a filter 32 for adjusting the intensity distribution of thelight emitted from the light source 3 is arranged on the light guide 20.The irradiating light is adjusted by the filter 32 to permit the lightintensity distribution to be made uniform within the light irradiatedregion. Also, a clearance is provided between the adjacent light guides20. By this particular construction, the edge of a light irradiatingregion is exactly aligned with the edge of the adjacent lightirradiating region. In other words, the adjacent light irradiatingregions do not overlap with each other.

[0151] For performing the heat treatment according to the fourthmodification of the second embodiment of the present invention, thesubstrate 1 equal to that shown in FIG. 1 is disposed on the substratesupport section 5, and the heat treatment is performed by the lightsource 3 as follows.

[0152] In the first step, a heat treatment is applied to a lightirradiated region 411 by the light source 3. After the heat treatmentapplied to the light irradiated region 411, a light irradiation isapplied to a light irradiating region 412 by using a light source 3differing from the light source 3 used for the first light irradiation,with the positions of the substrate 1 and the light source 3 heldstationary. It should be noted that the edge of the second lightirradiated region is aligned exactly with the edge of the first lightirradiated region. In other words, the adjacent light irradiated regionsdo not overlap with each other. The second light irradiation is startedafter the substrate 1 is cooled to, for example, room temperature. Inother words, the first light irradiation and the second lightirradiation do not overlap with each other in the light irradiatingtime.

[0153] Likewise, the third light irradiation to the ninth lightirradiation are carried out by each of the light sources 3, with thepositions of the substrate 1 and the light source 3 held stationary,such that the adjacent light irradiated regions do not overlap with eachother so as to finish the heat treatment over the entire region of thephotoresist film 103. Then, a developing treatment is applied to thephotoresist film 103 as in the first embodiment shown in FIG. 1,followed by patterning the light shielding film 102 so as to finishpreparation of a reticle.

[0154] In the fourth modification described above, the light sources 3are turned on one by one. However, it is possible to turn on a pluralityof light sources simultaneously. Further, all the light sources 3 can beturned on simultaneously. In other words, it is possible for theadjacent light irradiated regions to overlap with each other in thelight irradiating time.

[0155] [Third Embodiment]

[0156]FIG. 19 schematically shows the construction of a heat treatingapparatus according to a third embodiment of the present invention.

[0157] As in the first embodiment, a photo mask blank equipped with aphotoresist is used as the substrate 1.

[0158] AS in the first embodiment, a halogen lamp is used as the lightsource 3. A total of 25 halogen lamps are equidistantly arranged suchthat 5 halogen lamps are arranged in each of the X- and Y-directions.The light sources 3 slightly differ from each other in the irradiatinglight intensity, which is caused by the nonuniformity in the resistancevalues of the light sources 3. However, the difference in theirradiating light intensity can be detected in advance by measuring thelight irradiating intensities of the individual light sources 3. Itfollows that a suitable voltage is applied from the control device 6 toeach of the light sources 3 to achieve a uniform light irradiatingintensity.

[0159] The light guide 20 is arranged between the light source 3 and thesubstrate 1, and the filter 4 is arranged between the light source 3 andthe light guide 20. These basic constructions are equal to those of thefirst embodiment shown in FIG. 1.

[0160] The substrate support section 5 is arranged on the stage 50movable in the X-direction, Y-direction and Z-direction. The stage 50can be moved in a predetermined direction by the driving section 51. Thedriving section 51 is controlled by the control device 6. It should benoted that the stage 50 and the driving section 51 collectively form alight irradiating position moving mechanism for changing the lightirradiating position relative to the heating region of the substrate 1.

[0161] The light source support section 30 is connected to a lightirradiating position simple harmonic oscillating mechanism 70. Thesimple harmonic oscillating mechanism 70 permits the light sourcesupport section 30 (light irradiating position) to be repeatedlyreciprocated in a predetermined direction in the X-direction orY-direction relative to the heating region of the substrate 1. Thesimple harmonic oscillation is controlled by the control device 6.Incidentally, it is possible for the substrate support section 5 to besubjected to the simple harmonic oscillation in place of the lightsource support section 30.

[0162] The reflecting plate 15 is arranged above the substrate 1. Thereflecting plate 15 is equal to the reflecting plate used in the secondembodiment of the present invention. It is possible for the reflectingplate 15 to be equipped with a heater as in the second embodiment. Also,a black body plate or a light scattering plate can be used in place ofthe reflecting plate 15.

[0163] The third embodiment is equal to the first embodiment in respectof the apparatus outer frame 9, the dust filter 10, the chemical filter11 and the exhaust duct (not shown).

[0164] The heat treating method using the heat treating apparatus shownin FIG. 19 will now be described.

[0165] In the first step, the substrate 1 equal to that shown in FIG. 1is disposed on the substrate support section 5. The substrate 1 is setsuch that the center of the substrate 1 is aligned with the center ofthe light irradiating region of the light source 3 as viewed from above.

[0166] Then, the heating of the photoresist film 103 is started. Thesimple harmonic oscillation is started as soon as voltage is applied tothe light source 3. The amplitude of the oscillation is 24.7 mm (2^(½)/2times as large as the diameter of the light irradiated region), thecycle is 10 seconds, and the oscillation is performed in a direction of45° (i.e., the direction equal to the moving direction of the lightirradiated position shown in FIG. 7). Further, the irradiating time ofthe light source 3 is 200 seconds.

[0167] After completion of the heat treatment applied to the entiresurface of the photoresist film 103, the photoresist film 103 issubjected to a developing treatment as in the first embodiment, followedby patterning the light shielding film 102 so as to finish preparationof a reticle.

[0168] The reticle thus prepared was found to have a size error of 8 nm(3 σ) within the plane, supporting that it was possible to obtain a highprecision reticle (chromium mask).

[0169] In the third embodiment described above, the heat treatment wasapplied to the photoresist film 103 (heating region) while subjectingthe light irradiated region to the simple harmonic oscillation, makingit possible to apply the light irradiation a plurality of times to thatportion of the light irradiated region in which the light intensity islow so as to supplement the light intensity. It follows that the lightintensity distribution can be made uniform over the entire heatingregion. Particularly, since there is no boundary between the adjacentlight irradiated regions, it is possible to eliminate the nonuniformityin the total energy accompanying the light irradiation. It follows thatit is possible to markedly improve the concentric size distributionderived from the temperature distribution within a plane of the reticle.

[0170] Incidentally, in the third embodiment, it is possible to employin combination both the simple harmonic oscillating movement and therotary movement. It is also possible to subject the substrate 1 to thesimple harmonic oscillating movement.

[0171] [Fourth Embodiment]

[0172] The fourth embodiment is directed to the heat treatment informing an antireflection film on a semiconductor substrate (siliconwafer). Various methods described previously in conjunction with thevarious embodiments can be employed for the basic heat treatment.Specific examples will now be described.

[0173]FIG. 20A shows the gist portion of the heat treating apparatusaccording to the fourth embodiment of the present invention.

[0174] As shown in the drawing, a target substrate 500 prepared bycoating a silicon substrate with an antireflection film having athickness of 50 nm is disposed on the substrate support section 5. Thelight source 3 including 21 halogen lamps and the light guide 20 sized50 mm square are arranged above the target substrate 500.

[0175] After the target substrate 500 is disposed on the target supportsection 5, a heat treatment is applied to the light irradiated region501 shown in FIG. 20B by the light source 3. To be more specific, afterthe light source 3 is turned on, the heating is applied at a temperatureelevation rate of 40° C./sec. After the temperature is maintained at200° C. for 20 seconds, the light source 3 is turned off.

[0176] After the heat treatment applied to the light irradiated region501, the light irradiation is applied to a light irradiated region 502by a light source 3 differing from the light source 3 used in the firstlight irradiation. The second light irradiation is started after thesubstrate 500 is cooled to, for example, room temperature. In otherwords, the first light irradiation and the second light irradiation donot overlap with each other in the light irradiation time.

[0177] Likewise, the third light irradiation to the twenty-first lightirradiation are applied in the order denoted by an arrow in FIG. 20B bythe light source 3 so as to finish the heat treatment over the entireregion of the photoresist film 103.

[0178] The embodiment described above is directed to the heat treatmentfor forming an antireflection film on a silicon substrate. However, thepresent invention can be similarly applied to the heat treatment ofvarious films formed on a silicon substrate. For example, the presentinvention can be employed for the heat treatment applied to an SOG filmformed on a silicon substrate and for the heat treatment applied to aresist film on the antireflection film formed on a silicon substrate.

[0179] The first to fourth embodiments of the present inventiondescribed above can be employed for various heat treatments. Forexample, these embodiments can be employed for the thermal diffusiontreatment of the impurity ions implanted into a semiconductor substrateand for the thermal diffusion treatment of the impurity ions implantedinto a polycrystalline silicon (polysilicon) film. Further, the first tofourth embodiments of the present invention can be employed forimprovement of an oxide film formed on a semiconductor substrate.

[0180] Further, the present invention can be-employed for the heattreatment applied to a substrate of a liquid crystal display device,e.g., a transparent quartz glass substrate, particularly to aphotoresist film formed on the substrate, and for the manufacturingprocess of a color filter included in a liquid crystal display device.

[0181] As described above, in the first to fourth embodiments of thepresent invention, the light intensity distribution for the lightirradiation can be made uniform, and the temperature distribution in theheating region of or on a target substrate can also be made uniform.Further, a fine patterning process can be achieved with a high accuracyby making the temperature distribution uniform in the heating region.

[0182] [Fifth Embodiment]

[0183] A fifth embodiment of the present invention will now be describedwith reference to FIG. 21, which is directed to a trial manufacture of achromium mask used in the manufacturing process of a semiconductordevice.

[0184] In this embodiment, a chromium mask blank equipped with a resist,which has a size of 6 inches and a thickness of 0.25 inch, is used as atarget substrate 601. To be more specific, a target thin film 601 aconsisting of a chromium film and a resist film is formed on a quartzsubstrate 601 b so as to provide the target substrate 601.

[0185] Radiation thermometers 602 a and 602 b are arranged above thetarget substrate 601. The radiation thermometer 601 a mainly serves todetect the temperature information relating to the target thin film 601a, and the radiation thermometer 601 b mainly serves to detect thetemperature information relating to the quartz substrate 601 b. Thenumber of each of these radiation thermometers 602 a and 602 bcorresponds to the number of lamps. In other words, since 9 lamps areused, used are 9 radiation thermometers 602 a and 9 radiationthermometers 602 b. By arranging these radiation thermometers 602 a and602 b above the target substrate 601, the construction of the heattreating apparatus can be simplified.

[0186]FIG. 22 is a graph showing the relationship between the intensityof the light transmitting through the target substrate 601 and thewavelength of the transmitting light. As shown in the graph, theintensity of the transmitting light is substantially zero in thewavelength range between 2.68 and 2.84 μm and in the wavelength regionnot shorter than 4.31 μm by the effect of the target thin film 601 a. Inthe wavelength range between 2.84 μm and 4.31 μm, the light istransmitted to some extent through the target thin film 601 a and thequartz substrate 601 b. Such being the situation, the radiationthermometer 602 a is set to detect the light having a wavelength of 8 to14 μm, and the radiation thermometer 602 b is set to detect the lighthaving a wavelength of 2.8 to 4.3 μm. Incidentally, since the lighthaving a wavelength of 2.68 μm or less is transmitted to some extentthrough the target thin film 601 a and the quartz substrate 601 b, it ispossible to set the radiation thermometer 602 b to detect the lighthaving a wavelength of, for example, 2 to 2.7 μm.

[0187] Nine halogen lamps 603, which are positioned below the targetsubstrate 601, are equidistantly arranged to form a lattice consistingof 3 rows and 3 columns (3×3=9). Each halogen lamp 603 has a maximumoutput of 150 W and the wavelength at the maximum output is 1100 nm.

[0188] A filter 604 is arranged on the halogen lamp 603, and a lightguide 605 is arranged on the filter 604. The filter 604 is of aband-pass filter structure consisting of two filters capable of cuttingthe light components having wavelengths of about 1.4 μm and not shorterthan 2.2 μm, which are the light components absorbed by the quartzsubstrate 601 b. It follows that the light components emitted from thehalogen lamp 603 and passing through the filter 604 and light guide 605to reach the target substrate 601 serve to selectively heat the targetthin film 601 a while scarcely heating the quartz substrate 601 b.

[0189] A filter 620 for adjusting the intensity distribution of thelight emitted from the halogen lamp 603 is arranged on the light guide605. The irradiating light is adjusted by the filter 620 to permit thelight intensity distribution to be made uniform within the lightirradiated region. Also, a clearance is provided between adjacent lightguide 603. By the particular construction, the edge of a certain regionirradiated with the light emitted from the halogen lamp is exactlyaligned with the edge of the adjacent region irradiated with the lightemitted from the halogen lamp 603.

[0190] The target substrate 601 is supported by a mask support section606. The mask support section 606 consists of a main body made of astainless steel and mask support portions made of Teflon and serving tosupport the target substrate at four edge portions. A temperaturecontrol water flows inside the mask support section 606 so as to achievea temperature control.

[0191] The radiation thermometers 602 a and 602 b and the halogen lamp603 are controlled by a control section 607. To be more specific, thetemperature information obtained by the radiation thermometers 602 a and602 b, i.e., the temperature information for 9 sets of the radiationthermometers, is supplied to the control section 607, and the voltage orpower supplied to the halogen lamp 603 is controlled on the basis of thetemperature information supplied to the control section 607. It shouldbe noted that the 9 halogen lamps controlled independently.

[0192] In the control section 607, the following calculation is carriedout on the basis of the temperature information obtained by theradiation thermometers 602 a and 602 b.

[0193] Specifically, T_(s) represents the treating temperature of theheated section 601 a (the target temperature is 100° C. in thisembodiment), T₁(t) represents the temperature of the heated section 601a at time t, i.e., the time starting from the initiating step of theheat treatment, which is obtained on the basis of the temperatureinformation detected by the temperature detecting section 602 a, andT₂(t) represents the temperature of the quartz substrate 601 b at timet, which is obtained on the basis of the temperature informationdetected by the temperature detecting section 602 b.

[0194] Under the condition of the time t≦t_(a) (t_(a)=C×t₁ (0<C≦1)), thetime t₁ when T₁ is equal to T_(s), i.e., T₁=T_(s), is estimated on thebasis of the temperature T₁ of the heated section 601 a and thetemperature elevation rate δT₁/δt of the heated section 601 a. C, whichcan be set at an optional value, is set at 0.985, i.e., C=0.985. It ispossible to estimate the time t₁ further in view of δ²T₁/δt².

[0195] Under the condition of the time t≦t_(a), the output R(t) to thehalogen lamp 603 is determined by using the formula:

R(t)=F(T _(s) −T ₁ , δT ₁ /δt)

[0196] Also, under the condition of the time t>t_(a), the output R(t) tothe halogen lamp 603 is determined by using the formula:

G(T ₁ −T ₂)×H(δT ₁ /δt, δT ₂ /δt)

[0197] It is also possible to use variables of δ²T₁/δt² and δ²T₂/δt².

[0198] The target substrate 601 is transferred by a transfer arm 608.Also, in order to measure the temperature accurately, the measuringsystem is isolated from the disturbance by the apparatus outer frame 609so as to prevent turbulence of the gas stream. Also, an exhaust duct(not shown) is arranged in order to discharge the gas or the likegenerated during the heat treatment to the outside. The vapor of anorganic material or the like is prevented by the exhaust duct from beingattached to the inner wall of the heat treating apparatus. Further, adust filter 610 and a chemical filter 611 are arranged in order tocontrol the dust and the atmosphere within the apparatus.

[0199] An example of the heat treatment performed by using the apparatusshown in FIG. 21 will now be described.

[0200] In the first step, the target substrate 601 is prepared. Thetarget substrate 601 is prepared by coating a quartz substrate having aCr film formed thereon with a positive chemically amplified resist filmin a thickness of 500 nm, followed by applying an exposure to the coatedresist film by using an electron beam writing apparatus (50 keV, 7μC/cm²). After the position of the target substrate 601 is determined bya position determining unit (not shown), the target substrate 601 istransferred by the transfer arm 608 so as to be disposed on the masksupport section 606.

[0201] The temperature measurement by the radiation thermometers 602 aand 602 b are started as soon as the target substrate 601 is disposed onthe mask support section 606. The temperature measurement is started bya trigger signal supplied from the control section 607.

[0202] The period for taking the temperature data is set at 10 msec, andthe processing time is set at 40 sec. After the target substrate 601 isdisposed on the mask support section 606, the heating by the halogenlamp 603 is started. Also, the temperature data obtained by theradiation thermometers 602 a and 602 b are supplied to the controlsection 607.

[0203] During the heat treatment, the temperature T(t) of the targetthin film 601 a at the time t is calculated by using the formula:

T(t)=T ₁+(δT ₁ /δt)×Δt)

[0204] Also, the time t₁ when T(t) is elevated to reach the treatingtemperature (target temperature) T_(s) is calculated. In this example,t₁=10.00 seconds was calculated before arriving at the targettemperature. Also, the time t_(a) (=9.85 seconds) when the voltageapplication was changed was calculated on the basis of the numeral C(=0.985) set in advance in the control section 607.

[0205]FIG. 23 is a graph showing the change (a) of the temperature ofthe target thin film 601 a, the change (b) of the temperature of thequartz substrate 601 b, and the difference (c) between the temperaturesof the target thin film 601 a and the quartz substrate 601 b. For 9.85seconds after the voltage application, the heat treatment was performedunder the state that the output was 100% (100V, 150 W). The temperatureof the target thin film 601 a was found to have reached 100° C. about10.00 seconds later.

[0206] The voltage applied to the halogen lamp 603 after the time t_(a)(=9.85 seconds) was obtained by using the formula:

V=D×(T ₁ −T ₂)+

E×{(δT ₁ /δt)−(δT ₂ /δt)}Δt

[0207] D and E in the formula given above represents proportionalconstants. The applied voltage was calculated as required by using theformula given above so as to apply a suitable voltage to the halogenlamp 603. FIG. 24 shows the result. The reason for using the particularfunction is that, since a heat flow is generated in proportion to thedifference between the temperature of the light shielding film (Cr film)and the photosensitive film (resist film) and the temperature of thequartz substrate, the surface temperature of the substrate is consideredto be proportional to the heat flow under the state that an energy iskept supplied from the halogen lamp to the light shielding film and thephotosensitive film.

[0208] As described above, the target substrate is heated in view of notonly the temperature information of the light shielding film and thephotosensitive film on the substrate surface but also the temperatureinformation of the quartz substrate. As a result, it has been madepossible to carry out the heat treatment under the set temperatureT_(s)±0.2° C. with a very high accuracy both under the temperatureelevated state (T₁, T₂<T_(s)) and under a semi-stable state (T₁=T_(s),T₂<T_(s)) without bringing about hunting or the like even by the heatingutilizing the light irradiation having a very high response speed. Also,the temperature can be controlled with a high accuracy by independentlycontrolling the temperature for each irradiating region of the halogenlamp.

[0209] The temperature of the target thin film 601 a was kept atsubstantially 100° C. The voltage applied to the halogen lamp 603 waschanged to a very low voltage 40 seconds after initiation of the heattreatment so as to stop the heat treatment of the substrate. As shown inFIG. 23, the temperature of the quartz substrate 601 b when the heattreatment was stopped was about 70° C. The temperature of the resistfilm and the Cr film formed on the surface of the substrate was alsodropped instantly to 70° C. as soon as the voltage applied to thehalogen lamp was changed to a very low voltage.

[0210] After the heating was stopped, the target substrate 601 wastransferred by the transfer arm 608 into a cleaning unit, and thesubstrate was cooled.

[0211] Then, a dip development was applied by using AD-10 (manufacturedby Tama Kagaku K.K.), followed by applying a dry etching to the chromiumfilm. Further, the resist film was peeled and the washing was performed,followed by measuring the size of the chromium pattern within the maskplane (130 mm square) by using an SEM. The planar uniformity of the sizeof the chromium pattern was found to be 9.8 nm (3 σ), supporting that itwas possible to obtain a chromium pattern excellent in uniformity.

[0212] [Sixth Embodiment]

[0213] A sixth embodiment of the present invention will now be describedwith reference to FIG. 25, which is directed to a trial manufacture of achromium mask used in a manufacturing process of a semiconductor device.

[0214] The basic construction of the apparatus is equal to that of theapparatus shown in FIG. 1. In the apparatus shown in FIG. 25, theradiation thermometer 602 b for detecting mainly the temperatureinformation relating to the quartz substrate 601 b is arranged below thetarget substrate 601.

[0215] The radiation thermometer 602 b serves to detect the lightcomponents having a wavelength of 2 to 4.3 μm. Since the quartzsubstrate 601 b is translucent to the light components of the wavelengthnoted above, it is possible to measure the temperature inside the quartssubstrate (in the vicinity of the light shielding film). The radiationthermometer 602 a serves to detect the light components having awavelength of 8 to 14 μm, as in the fifth embodiment. It is possible todetect selectively the temperature of the quartz substrate alone byarranging the radiation thermometer 602 b below the target substrate 601and by setting appropriately the wavelength of the light componentdetected by the radiation thermometer 602 b.

[0216] A PID control was employed for the control. The control section607 has a function of calculating the PID constant for determining theoutput R(t) to the halogen lamp 603 on the basis of the temperatureT₁(t) of the target heating section 601 a at the time t, which isobtained on the basis of the temperature information detected by thetemperature detecting section 602 a, and the temperature T₂(t) of thequartz substrate 601 b at the time t, which is obtained on the basis ofthe temperature information detected by the temperature detectingsection 602 b. The substrate treating temperature T_(s) was set at 100°C. as in the fifth embodiment.

[0217] The PID constant, which is considered to be the best byexperience, is inputted in the initial setting time. After initiation ofthe heating, the changes with time in temperatures of the target heatingsection 601 a and the quartz substrate 601 b are estimated by using theformulas {T₁(t)−T₂(t)}, {δT₁(t)/δt}−{δT₂(t)/δt}, {δ²T₁(t)/δt²}, and{δ²T₂(t)/δt²} on the basis of the temperature T₁(t) of the targetheating section 601 a and the temperature T₂(t) of the quartz substrate601 b at the time t. The optimum PID constant is determined on the basisof the period and amplitude of the vibration obtained on the basis ofthe result of the estimation. Since the optimum PID constant isdetermined as required during the heating treatment, it is possible toperform the control with the optimum PID constant in accordance with thechanges in temperature of the target heating section 601 a and thequarts substrate 601 b.

[0218] A target substrate 601 equal to that used in the fifth embodimentwas disposed on the mask support section 606.

[0219] The period for taking the temperature data was set at 10 msec,and the treating time was set at 60 sec. After the target substrate 601was disposed on the mask support section 606, the heating treatmentusing the halogen lamp 603 was started. Also, the temperature dataobtained by the radiation thermometers 602 a and 602 b were supplied tothe control section 607. FIG. 26 is a graph showing the change (a) intemperature of the target thin film 601 a, the change (b) in temperatureof the quartz substrate, and the difference (c) between the temperatureof the target thin film 601 a and the temperature of the quartzsubstrate 1 b.

[0220] Where the temperatures of the target thin film 601 a and thequartz substrate 601 b are lower than the set temperature T_(s), i.e.,T₁, T₂<T_(s), immediately after lighting of the lamp, the values of P=5(%), I=4 (sec), and D=1 (sec) were inputted as default values as acombination of the control constants for the PID control.

[0221] The control constants for PID were changed in accordance with thetemperature data of T₁ and T₂ as soon as the temperature T₁ of thetarget heating section 601 a was changed to the set value (T₁=T_(s))about 10 seconds after the lamp was lit so as to control the output ofthe halogen lamp.

[0222] As a result, it has been found that it is possible to carry outthe heat treatment with a very high accuracy, i.e., at the settemperature T_(s)±0.2° C., under both the temperature elevated state(T₁, T₂<T_(s)) and the semi-stable state (T₁=T_(s), T₂<T_(s)) withoutgiving rise to the hunting or an off-set error even in the system inwhich the response speed of the surface temperature is changed at alltimes. Also, it was possible to carry out the temperature control with ahigh accuracy by performing the temperature control independently foreach irradiating region of the halogen lamp.

[0223] After the heating of the substrate was stopped, the targetsubstrate 601 was transferred by using the transfer arm 608 into acleaning unit, and the substrate was cooled.

[0224] Then, a dip development was performed, followed by applying a dryetching to the chromium film. Further, the resist film was peeled, andthe washing was performed, followed by measuring the size of thechromium pattern by SEM within the mask plane (130 mm square). It hasbeen found that the planar uniformity of the size of the chromiumpattern was 9.8 nm (3 σ), supporting that it is possible to obtain achromium pattern excellent in uniformity.

[0225] In the sixth embodiment described above, the PID constant iscalculated by estimating in advance the temperature. Alternatively, itis also possible to input in advance the PID constant that is consideredto be the most appropriate in accordance with the temperature differencebetween the target heating section and the quartz substrate.

[0226] As described above, according to the fifth and sixth embodimentsof the present invention, the heating section is controlled in view ofthe temperature T₂ of the base substrate in addition to the treatingtemperature T_(s) of the thin film and the temperature T₁ of the thinfilm, making it possible to carry out the temperature with a highaccuracy. In other words, it is possible to apply a heat treatment to athin film with a high accuracy.

[0227] Additional advantages and modifications will readily occur tothose skilled in the art. Therefore, the invention in its broaderaspects is not limited to the specific details and representativeembodiments shown and described herein. Accordingly, variousmodifications may be made without departing from the spirit or scope ofthe general inventive concept as defined by the appended claims andtheir equivalents.

What is claimed is:
 1. A heat treating method for heating a targetsubstrate by means of light irradiation, wherein a light irradiationtreatment is applied a plurality of times to said target substrate suchthat the adjacent light irradiating regions of said target substrate areallowed to partially overlap each other and that the light irradiatingperiods of the adjacent light irradiating regions do not overlap witheach other.
 2. The heat treating method according to claim 1, whereinthe light irradiation treatment that is applied a plurality of times tosaid target substrate is performed by changing the light irradiatingregions by a predetermined order such that the adjacent lightirradiating regions are allowed to partially overlap with each other. 3.The heat treating method according to claim 1, wherein the lightirradiation treatment that is applied a plurality of times to saidtarget substrate is performed by a plurality of irradiating lightgenerating sections arranged to conform with the light irradiatingregions and arranged such that the adjacent light irradiating regionsare allowed to partially overlap with each other.
 4. A heat treatingmethod for heating a target substrate by means of light irradiation,wherein a light irradiation treatment is applied to said targetsubstrate such that the light irradiating regions of said targetsubstrate do not overlap with each other, said light irradiationtreatment being performed by using an irradiating light adjusted suchthat the distribution of the light intensity within the lightirradiating region of the target substrate is rendered uniform.
 5. Theheat treating method according to claim 4, wherein the light irradiationtreatment applied to the target substrate is performed by changing thelight irradiating regions by a predetermined order such that the lightirradiating regions do not overlap with each other.
 6. The heat treatingmethod according to claim 4, wherein the light irradiation treatmentapplied to the target substrate is performed by using a plurality ofirradiating light generating sections arranged to conform with the lightirradiating regions and arranged such that the light irradiating regionsdo not overlap with each other.
 7. A heat treating apparatus for heatinga target substrate by means of light irradiation, comprising: asubstrate support section for supporting said target substrate; anirradiating light generating section for irradiating the lightirradiating regions of the target substrate supported by said substratesupport section; and a light irradiating region changing section forchanging the light irradiating regions of the target substrateirradiated with the light generated from the irradiating lightgenerating section.
 8. A heat treating apparatus for heating a targetsubstrate by means of light irradiation, comprising: a substrate supportsection for supporting said target substrate; a plurality of irradiatinglight generating sections arranged to conform with the light irradiatingregions of the target substrate supported by said substrate supportsection and arranged such that the light irradiating regions do notoverlap with each other, said irradiating light generating sectiongenerating an irradiating light adjusted to permit the light intensitydistribution to be uniform within the light irradiating region of thetarget substrate.
 9. A heat treating method for heating a targetsubstrate consisting of a base substrate and a thin film formed on thebase substrate by a heating section, comprising: detecting temperatureinformation relating to temperature T₁ of said thin film and temperatureT₂ of said base substrate; and controlling said heating section on thebasis of temperature T₁ of the thin film, temperature T₂ of the basesubstrate, which are obtained from said temperature information, and atarget temperature T_(s) at which said thin film is to arrive.
 10. Theheat treating method according to claim 9, wherein a plurality ofheating periods differ from each other in the control characteristics ofthe heating section.
 11. The heat treating method according to claim 10,wherein said control characteristics are represented by a functionincluding the temperature T₁ of the thin film and the temperature T₂ ofthe base substrate in at least one heating period.
 12. The heat treatingmethod according to claim 10, wherein said control characteristics aremade different at time t_(a) when, or before, the temperature T₁ of thethin film arrives at the target temperature TS.
 13. The heat treatingmethod according to claim 12, wherein said time t_(a) is determined byestimating the time when the temperature T₁ of the thin film will arriveat the target temperature T_(s) on the basis of the temperature T₁ ofthe thin film and the elevation rate of the temperature T₁ and byutilizing the result of the estimation.
 14. A heat treating apparatusfor heating a target substrate consisting of a base substrate and a thinfilm formed on the base substrate, comprising: a heating section forheating the target substrate; a temperature detecting section fordetecting temperature information relating to temperature T₁ of the thinfilm and temperature T₂ of the base substrate; and a control section forcontrolling said heating section on the basis of the temperature T₁ ofthe thin film, the temperature T₂ of the base substrate, which areobtained from the temperature information detected by said temperaturedetecting section, and a target temperature T_(s) at which said thinfilm is to arrive.
 15. The heat treating apparatus according to claim14, wherein the temperature detecting section has a first detectingsection and a second detecting section each arranged on the side of thatsurface of the base substrate on which the thin film is formed, saidfirst detecting section serving to detect a light having a wavelengththat permits the temperature information of the thin film to beselectively obtained, and said second detecting section serving todetect a light having a wavelength that permits the temperatureinformation of at least the base substrate to be obtained.
 16. The heattreating apparatus according to claim 14, wherein the temperaturedetecting section has a first detecting section arranged on the side ofa first surface of the base substrate on which said thin film is formedand a second detecting section arranged on the side of a second surfaceof the base substrate which is opposite to the first surface, said firstdetecting section serving to detect a light having a wavelength thatpermits the temperature information of the thin film to be selectivelyobtained, and said second detecting section serving to detect a lighthaving a wavelength that permits the temperature information of at leastthe base substrate to be obtained.